Hi there!
I'm sorry the game caused you to have motion sickness! I'd love for there to be a third-person view, but I wasn't able to do it while the game was in development back in 2015 and it's unfortunately not feasible to add to the game at this point for various reasons. You may be able to mitigate your motion sickness by increasing the field of view in the game settings and/or playing in windowed mode rather than fullscreen though.
I am, however, currently working on a remaster of the game which is more likely to get a third-person view at some point. It'll also have an increased default field of view to help with motion sickness as well.
Chris